import java.util.Scanner;

public class Day_9_2_走方格的方案数 {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int i = sc.nextInt();
        int j = sc.nextInt();
        int counts = count(i, j);
        System.out.println(counts);
    }

    private static int count(int i, int j){
        if(i == 0 || j == 0){
            return 1;
        }
        return count(i-1, j) + count(i, j-1);
    }
}
